The present invention relates to a method of reading data in a non-volatile memory device for reducing a read disturbance phenomenon.
Recently, the demand has increased for a non-volatile memory device which electrically programs and erases data and does not need to have a periodical refresh function.
The non-volatile memory device generally includes a memory cell array where memory cells for storing data are formed, and a page buffer for programming and reading data to/from a specific memory cell of the memory cell array.
The page buffer has a pair of bit lines connected to a certain memory cell, a register for temporarily storing data to be programmed to the memory cell array or reading data from a certain memory cell in the memory cell array and storing temporarily the read data, a sensing node for sensing a bit line or a voltage level of the register, and a bit line selecting section for controlling the connection between the bit line and the sensing node.
In the above read operation of the non-volatile memory device, a first voltage is applied to a bit line connected to a cell string having a certain memory cell, and a second voltage is provided to a bit line not connected to the cell string. Here, the second voltage is different from the first voltage.
In the case that a read voltage Vread is applied to a word line of a first memory cell related to the bit line not connected to the cell string during the read operation is performed, a hot carrier injection phenomenon can occur to a second memory cell adjacent to the first memory cell. As a result, a read disturbance phenomenon may occur to the non-volatile memory device due to the hot carrier injection phenomenon.